Continuous optode fluorescent measurement system

Abstract

Presently described are systems and methods for the continuous, accurate, low cost measurement of the concentration of target molecule(s), e.g., analytes, such as metabolites and ions, using analyte-specific, light-emitting agents, e.g., fluorescent nanosensors.

1 . An optical sensor (optode) system comprising:
 (i) at least one analyte-specific, light-emitting agent, which emits light in the presence of the analyte;   (ii) a sensor device configured to detect non-invasively the light emitted by the agent, the sensor device comprising a plurality of LEDs, at least one photodiode configured to detect light emitted from the light-emitting agent, an SOC/microprocessor, and transceiver to receive/transmit data wirelessly and, optionally, a photodiode light filter; and   (iii) a display, wherein the system is configured such that the sensor quantifies the in vivo levels or concentration of the analyte and displays the information graphically on the display.   
     
     
         2 . The system of  claim 1 , wherein the sensor device comprises two LEDs. 
     
     
         3 . The system of  claim 1 , wherein the LEDs are located near or in apposition to the photodiode or window thereof. 
     
     
         4 . The system of  claim 1 , wherein the sensor device further comprises an OpAmp, an ADC, an encrypted memory or a combination thereof. 
     
     
         5 . The system of  claim 1 , wherein the display is a hand-held device display or a computer data website or both. 
     
     
         6 . The system of  claim 1 , wherein the analyte is selected from the group consisting of glucose, sodium, potassium, calcium, chloride, and a combination thereof. 
     
     
         7 . The system of  claim 1 , wherein the system is further configured to acquire continuous real-time measurement of the analyte concentration. 
     
     
         8 . The system of  claim 1 , further comprising a drug delivery device in communication with the sensor. 
     
     
         9 . The system of  claim 1 , further comprising at least one additional sensor which detects or measures a vital sign in a subject, wherein the vital sign is blood pressure, heart rate, temperature or a combination thereof. 
     
     
         10 . A method of monitoring an analyte in a patient non-invasively comprising the steps of:
 administering an analyte-specific, light-emitting agent, which emits light in the presence of the analyte;   providing an optical sensor system comprising a sensor device comprising a plurality of LEDs, at least one photodiode configured to detect light emitted from the light-emitting agent, an SOC/microprocessor, a transceiver for receiving/transmitting data wirelessly, and a display, wherein the sensor device is configured to detect and measure non-invasively the light emitted by the agent, calculate the amount or concentration of analyte present;   detecting and measuring the intensity of light emitted by the analyte-specific light-emitting agent over a predetermined time course with the sensor device, wherein the sensor device calculates the amount or concentration of analyte present based on the intensity of light emitted by the light-emitting agent over the predetermined time course;   transmitting the light emission data to a second processor having a display;   displaying graphically the amount or concentration of the analyte detected by the sensor device over the predetermined time course.   
     
     
         11 . The method of  claim 10 , wherein the sensor device comprises LEDs. 
     
     
         12 . The method of  claim 12 , wherein the LEDs emit light at about 460 nm. 
     
     
         13 . The method of  claim 10 , wherein the analyte is selected from the group consisting of glucose, sodium, potassium, calcium, chloride, and a combination thereof. 
     
     
         14 . The method of  claim 13 , wherein the analyte is glucose. 
     
     
         15 . A method for normalizing opamp circuit gain in an LED-based fluorescence detecting sensor device comprising the steps of:
 providing at least two LEDs that provide different intensities of 460 nm wavelength of light, wherein at least one LED is biased with about 5 mA of current, and at least one other LED is biased at 2.5 mA of current;   alternating the power to the respective LEDs such that they are ON and OFF at different times; and   acquiring analyte measurements with (i) the 5 mA LED ON, and 2.5 mA LED OFF, (ii) the 5 mA LED OFF, and 2.5 mA LED ON, and (iii) both the 5 mA LED ON and the 2.5 mA LED ON.